1. Field
The subject matter disclosed herein relates to power management of a mobile station.
2. Information
Mobile stations such as, for example, cellular telephones, may provide voice communication through wireless communication with a network of terrestrial cell towers, sometimes referred to as base stations. As part of the voice communication process, cellular telephones continually detect pilot signals transmitted from a number of base stations and report detected signals and their associated signal strengths to a controlling base station. Handovers from one controlling base station to another may occur as the cellular telephone moves from one cell area to another in order to ensure uninterrupted conversation. Handover decisions may be made by the cellular network at least in part based on the reported signal strengths. The cellular telephone receives the pilot signals and reports signal strengths even when the phone is not engaged in a call.
Smart phones, as another example of a mobile station, may include enhanced functionality beyond voice communication. Features that may be included in a smart phone may include 3D graphics, music player, enterprise networking applications, camera, personal digital assistant functions, text messaging, email, and internet browser, to name a few example features. Mobile stations may further incorporate, in some cases, sensors. Such sensors may include accelerometers, barometers, and gyroscopes, to name a few examples. Sensors such as those listed may be based on microelectromechanical systems (MEMS) technology, for example.
Mobile stations may also provide navigation functions. Satellite positioning systems (SPS) such as, for example, the Global Positioning System (GPS), may provide navigation information to mobile stations in many circumstances. To gather information in order to determine a position location, a mobile station may receive timing signals from an SPS. Such information may be utilized by the mobile station to estimate the position location, or the mobile station may provide the information to a network entity, perhaps accessed via a cellular network for one example, for position location estimation. Navigation operations may also be based, at least in part, on signals received from cellular base stations and/or on information generated by one or more MEMS sensors, in some mobile stations.
The various features mentioned above for mobile stations may result in a relatively high rate of power consumption. Further, mobile stations may on occasion be utilized under conditions that may result in relatively burdensome power consumption. For example, a mobile station carried onto an airplane and traveling at several hundred miles per hour relative to the ground may experience difficulties in acquiring and maintaining communication with base stations on the ground, and may also experience difficulty in performing position location operations. For merely one example of a burdensome power consumption scenario, consider that a mobile station traveling in an airplane may continually attempt to acquire terrestrial base stations in order to establish communications. Such repeated attempts to acquire a base station may result in relatively high power consumption that may drain the mobile station's battery relatively quickly. Similarly, performing position location operations that may result in inaccurate location information due to the high rate of speed may waste power.
Also, due in part to the mobile station's continual transmission of signals even if not engaged in a call, users traveling by air are required to shutdown the mobile station during flight in order to conform with Federal Aviation Administration (FAA) regulations against signal transmission from electronic devices carried by passengers during flight. If the user forgets to power down the mobile station when preparing for take off, the relatively high rates of power consumption may significantly or completely drain the mobile station's battery by the time the user arrives at the destination. Further, failure by the user to power down the mobile station will result in a violation of FAA regulations that are intended to make air travel more safe.